Only about 60 to 90% of incubated eggs hatch in commercial hatcheries. Non hatching eggs include infertile eggs or fertile eggs in which the embryos had died during incubation. Infertile eggs, usually comprising up to 25% of all eggs, can find useful applications as commercial table eggs or low grade food stock if they are detected early and isolated accordingly prior to incubation. Discarding of non-hatching eggs has consistently posed significant disposal problems for hatcheries, especially in the case of exploder eggs in a hatching cabinet, resulting in high tendency of transferring molds and bacteria infestation to other eggs. Thus, identification and isolation of infertile eggs have significant economic and safety implications for commercial broiler breeders.
Candling is a technique which illuminates the interior of the egg for the purpose of detecting dead or infertile eggs. However, candling is laborious and prone to errors. Studies have shown that only 5% of total eggs can be candled after ten days of incubation. The difficulty of separating the non-fertile eggs from the remaining non-candled 95% of eggs makes this technique unadoptable to industrial and large scale operations.
The sex of fertile eggs is also among the egg characteristics of interest for the poultry industry. In the layer egg industry, chicks are sexed at hatch and the female birds (that will lay eggs) are considered paramount while the male birds are culled. The opposite is the case with the broiler industry in which the male species are crucial. In either case, discarding of the unwanted chicks creates serious bottlenecks as far as waste disposal and animal welfare issues are concerned.
Several approaches have been used to determine the gender of fertile eggs based on molecular and hormone assays that are laborious and invasive in nature. The techniques are of limited use in the industry as they are unsuitable for automated, high throughput applications.
Other approaches have used computer vision and spectroscopy to determine gender and/or fertility of unhatched eggs. However, such approaches have suffered from various drawbacks, including for example, poor performance on brown eggs, being limited in the data considered (e.g., limited to spatial data or limited to spectral data), being tested only on artificially fertilized eggs, etc.
Therefore, there is a need for improved technology for detecting gender and/or fertility of unhatched eggs.